Retractable cutting tool holders are generally known for use with boring machines and turret latches, which have the work piece rotated relative to the work tool, and wherein a compression spring in the holder is used to retract the actual cutting element just before the tool is withdrawn from the work piece.
In this regard, general reference is made to the BOKUMATIC tool, model K, made by the Bokum Tool Company of Madison Heights, Mich., which will be more fully described in the discussion of the present invention which follows hereinafter.
One noticeable problem with such retractable tool holders is that the compression spring does not allow as quick and rapid a retraction as is desirable since the means for positively positioning the cutting tool and providing back-up support must be retracted or withdrawn before the retracting spring is effective. Consequently, tool witness mark such as spiraling or rifling frequently occur and although this can be avoided by shutting down the machine, before the cutting tool is retracted and withdrawn, the down time is obviously undesirable.
What is needed is a means for actuating and setting the cutting tool for a precision cut, providing the necessary support for the work to be done by the cutting tool, and subsequent being able to simultaneously remove the tool support and retract the tool to avoid leaving any tool witness marks.